
package ch.ethz.ssh2.crypto.cipher;

/*
 This file was shamelessly taken from the Bouncy Castle Crypto package.
 Their licence file states the following:

 Copyright (c) 2000 - 2004 The Legion Of The Bouncy Castle
 (http://www.bouncycastle.org)

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE. 
 */

/**
 * A class that provides Blowfish key encryption operations, such as encoding
 * data and generating keys. All the algorithms herein are from Applied
 * Cryptography and implement a simplified cryptography interface.
 * 
 * @author See comments in the source file
 * @version $Id: BlowFish.java,v 1.3 2005/12/05 17:13:27 cplattne Exp $
 */
public class BlowFish implements BlockCipher
{

	private final static int[] KP = { 0x243F6A88, 0x85A308D3, 0x13198A2E, 0x03707344, 0xA4093822, 0x299F31D0,
			0x082EFA98, 0xEC4E6C89, 0x452821E6, 0x38D01377, 0xBE5466CF, 0x34E90C6C, 0xC0AC29B7, 0xC97C50DD, 0x3F84D5B5,
			0xB5470917, 0x9216D5D9, 0x8979FB1B },

	KS0 = { 0xD1310BA6, 0x98DFB5AC, 0x2FFD72DB, 0xD01ADFB7, 0xB8E1AFED, 0x6A267E96, 0xBA7C9045, 0xF12C7F99, 0x24A19947,
			0xB3916CF7, 0x0801F2E2, 0x858EFC16, 0x636920D8, 0x71574E69, 0xA458FEA3, 0xF4933D7E, 0x0D95748F, 0x728EB658,
			0x718BCD58, 0x82154AEE, 0x7B54A41D, 0xC25A59B5, 0x9C30D539, 0x2AF26013, 0xC5D1B023, 0x286085F0, 0xCA417918,
			0xB8DB38EF, 0x8E79DCB0, 0x603A180E, 0x6C9E0E8B, 0xB01E8A3E, 0xD71577C1, 0xBD314B27, 0x78AF2FDA, 0x55605C60,
			0xE65525F3, 0xAA55AB94, 0x57489862, 0x63E81440, 0x55CA396A, 0x2AAB10B6, 0xB4CC5C34, 0x1141E8CE, 0xA15486AF,
			0x7C72E993, 0xB3EE1411, 0x636FBC2A, 0x2BA9C55D, 0x741831F6, 0xCE5C3E16, 0x9B87931E, 0xAFD6BA33, 0x6C24CF5C,
			0x7A325381, 0x28958677, 0x3B8F4898, 0x6B4BB9AF, 0xC4BFE81B, 0x66282193, 0x61D809CC, 0xFB21A991, 0x487CAC60,
			0x5DEC8032, 0xEF845D5D, 0xE98575B1, 0xDC262302, 0xEB651B88, 0x23893E81, 0xD396ACC5, 0x0F6D6FF3, 0x83F44239,
			0x2E0B4482, 0xA4842004, 0x69C8F04A, 0x9E1F9B5E, 0x21C66842, 0xF6E96C9A, 0x670C9C61, 0xABD388F0, 0x6A51A0D2,
			0xD8542F68, 0x960FA728, 0xAB5133A3, 0x6EEF0B6C, 0x137A3BE4, 0xBA3BF050, 0x7EFB2A98, 0xA1F1651D, 0x39AF0176,
			0x66CA593E, 0x82430E88, 0x8CEE8619, 0x456F9FB4, 0x7D84A5C3, 0x3B8B5EBE, 0xE06F75D8, 0x85C12073, 0x401A449F,
			0x56C16AA6, 0x4ED3AA62, 0x363F7706, 0x1BFEDF72, 0x429B023D, 0x37D0D724, 0xD00A1248, 0xDB0FEAD3, 0x49F1C09B,
			0x075372C9, 0x80991B7B, 0x25D479D8, 0xF6E8DEF7, 0xE3FE501A, 0xB6794C3B, 0x976CE0BD, 0x04C006BA, 0xC1A94FB6,
			0x409F60C4, 0x5E5C9EC2, 0x196A2463, 0x68FB6FAF, 0x3E6C53B5, 0x1339B2EB, 0x3B52EC6F, 0x6DFC511F, 0x9B30952C,
			0xCC814544, 0xAF5EBD09, 0xBEE3D004, 0xDE334AFD, 0x660F2807, 0x192E4BB3, 0xC0CBA857, 0x45C8740F, 0xD20B5F39,
			0xB9D3FBDB, 0x5579C0BD, 0x1A60320A, 0xD6A100C6, 0x402C7279, 0x679F25FE, 0xFB1FA3CC, 0x8EA5E9F8, 0xDB3222F8,
			0x3C7516DF, 0xFD616B15, 0x2F501EC8, 0xAD0552AB, 0x323DB5FA, 0xFD238760, 0x53317B48, 0x3E00DF82, 0x9E5C57BB,
			0xCA6F8CA0, 0x1A87562E, 0xDF1769DB, 0xD542A8F6, 0x287EFFC3, 0xAC6732C6, 0x8C4F5573, 0x695B27B0, 0xBBCA58C8,
			0xE1FFA35D, 0xB8F011A0, 0x10FA3D98, 0xFD2183B8, 0x4AFCB56C, 0x2DD1D35B, 0x9A53E479, 0xB6F84565, 0xD28E49BC,
			0x4BFB9790, 0xE1DDF2DA, 0xA4CB7E33, 0x62FB1341, 0xCEE4C6E8, 0xEF20CADA, 0x36774C01, 0xD07E9EFE, 0x2BF11FB4,
			0x95DBDA4D, 0xAE909198, 0xEAAD8E71, 0x6B93D5A0, 0xD08ED1D0, 0xAFC725E0, 0x8E3C5B2F, 0x8E7594B7, 0x8FF6E2FB,
			0xF2122B64, 0x8888B812, 0x900DF01C, 0x4FAD5EA0, 0x688FC31C, 0xD1CFF191, 0xB3A8C1AD, 0x2F2F2218, 0xBE0E1777,
			0xEA752DFE, 0x8B021FA1, 0xE5A0CC0F, 0xB56F74E8, 0x18ACF3D6, 0xCE89E299, 0xB4A84FE0, 0xFD13E0B7, 0x7CC43B81,
			0xD2ADA8D9, 0x165FA266, 0x80957705, 0x93CC7314, 0x211A1477, 0xE6AD2065, 0x77B5FA86, 0xC75442F5, 0xFB9D35CF,
			0xEBCDAF0C, 0x7B3E89A0, 0xD6411BD3, 0xAE1E7E49, 0x00250E2D, 0x2071B35E, 0x226800BB, 0x57B8E0AF, 0x2464369B,
			0xF009B91E, 0x5563911D, 0x59DFA6AA, 0x78C14389, 0xD95A537F, 0x207D5BA2, 0x02E5B9C5, 0x83260376, 0x6295CFA9,
			0x11C81968, 0x4E734A41, 0xB3472DCA, 0x7B14A94A, 0x1B510052, 0x9A532915, 0xD60F573F, 0xBC9BC6E4, 0x2B60A476,
			0x81E67400, 0x08BA6FB5, 0x571BE91F, 0xF296EC6B, 0x2A0DD915, 0xB6636521, 0xE7B9F9B6, 0xFF34052E, 0xC5855664,
			0x53B02D5D, 0xA99F8FA1, 0x08BA4799, 0x6E85076A },

	KS1 = { 0x4B7A70E9, 0xB5B32944, 0xDB75092E, 0xC4192623, 0xAD6EA6B0, 0x49A7DF7D, 0x9CEE60B8, 0x8FEDB266, 0xECAA8C71,
			0x699A17FF, 0x5664526C, 0xC2B19EE1, 0x193602A5, 0x75094C29, 0xA0591340, 0xE4183A3E, 0x3F54989A, 0x5B429D65,
			0x6B8FE4D6, 0x99F73FD6, 0xA1D29C07, 0xEFE830F5, 0x4D2D38E6, 0xF0255DC1, 0x4CDD2086, 0x8470EB26, 0x6382E9C6,
			0x021ECC5E, 0x09686B3F, 0x3EBAEFC9, 0x3C971814, 0x6B6A70A1, 0x687F3584, 0x52A0E286, 0xB79C5305, 0xAA500737,
			0x3E07841C, 0x7FDEAE5C, 0x8E7D44EC, 0x5716F2B8, 0xB03ADA37, 0xF0500C0D, 0xF01C1F04, 0x0200B3FF, 0xAE0CF51A,
			0x3CB574B2, 0x25837A58, 0xDC0921BD, 0xD19113F9, 0x7CA92FF6, 0x94324773, 0x22F54701, 0x3AE5E581, 0x37C2DADC,
			0xC8B57634, 0x9AF3DDA7, 0xA9446146, 0x0FD0030E, 0xECC8C73E, 0xA4751E41, 0xE238CD99, 0x3BEA0E2F, 0x3280BBA1,
			0x183EB331, 0x4E548B38, 0x4F6DB908, 0x6F420D03, 0xF60A04BF, 0x2CB81290, 0x24977C79, 0x5679B072, 0xBCAF89AF,
			0xDE9A771F, 0xD9930810, 0xB38BAE12, 0xDCCF3F2E, 0x5512721F, 0x2E6B7124, 0x501ADDE6, 0x9F84CD87, 0x7A584718,
			0x7408DA17, 0xBC9F9ABC, 0xE94B7D8C, 0xEC7AEC3A, 0xDB851DFA, 0x63094366, 0xC464C3D2, 0xEF1C1847, 0x3215D908,
			0xDD433B37, 0x24C2BA16, 0x12A14D43, 0x2A65C451, 0x50940002, 0x133AE4DD, 0x71DFF89E, 0x10314E55, 0x81AC77D6,
			0x5F11199B, 0x043556F1, 0xD7A3C76B, 0x3C11183B, 0x5924A509, 0xF28FE6ED, 0x97F1FBFA, 0x9EBABF2C, 0x1E153C6E,
			0x86E34570, 0xEAE96FB1, 0x860E5E0A, 0x5A3E2AB3, 0x771FE71C, 0x4E3D06FA, 0x2965DCB9, 0x99E71D0F, 0x803E89D6,
			0x5266C825, 0x2E4CC978, 0x9C10B36A, 0xC6150EBA, 0x94E2EA78, 0xA5FC3C53, 0x1E0A2DF4, 0xF2F74EA7, 0x361D2B3D,
			0x1939260F, 0x19C27960, 0x5223A708, 0xF71312B6, 0xEBADFE6E, 0xEAC31F66, 0xE3BC4595, 0xA67BC883, 0xB17F37D1,
			0x018CFF28, 0xC332DDEF, 0xBE6C5AA5, 0x65582185, 0x68AB9802, 0xEECEA50F, 0xDB2F953B, 0x2AEF7DAD, 0x5B6E2F84,
			0x1521B628, 0x29076170, 0xECDD4775, 0x619F1510, 0x13CCA830, 0xEB61BD96, 0x0334FE1E, 0xAA0363CF, 0xB5735C90,
			0x4C70A239, 0xD59E9E0B, 0xCBAADE14, 0xEECC86BC, 0x60622CA7, 0x9CAB5CAB, 0xB2F3846E, 0x648B1EAF, 0x19BDF0CA,
			0xA02369B9, 0x655ABB50, 0x40685A32, 0x3C2AB4B3, 0x319EE9D5, 0xC021B8F7, 0x9B540B19, 0x875FA099, 0x95F7997E,
			0x623D7DA8, 0xF837889A, 0x97E32D77, 0x11ED935F, 0x16681281, 0x0E358829, 0xC7E61FD6, 0x96DEDFA1, 0x7858BA99,
			0x57F584A5, 0x1B227263, 0x9B83C3FF, 0x1AC24696, 0xCDB30AEB, 0x532E3054, 0x8FD948E4, 0x6DBC3128, 0x58EBF2EF,
			0x34C6FFEA, 0xFE28ED61, 0xEE7C3C73, 0x5D4A14D9, 0xE864B7E3, 0x42105D14, 0x203E13E0, 0x45EEE2B6, 0xA3AAABEA,
			0xDB6C4F15, 0xFACB4FD0, 0xC742F442, 0xEF6ABBB5, 0x654F3B1D, 0x41CD2105, 0xD81E799E, 0x86854DC7, 0xE44B476A,
			0x3D816250, 0xCF62A1F2, 0x5B8D2646, 0xFC8883A0, 0xC1C7B6A3, 0x7F1524C3, 0x69CB7492, 0x47848A0B, 0x5692B285,
			0x095BBF00, 0xAD19489D, 0x1462B174, 0x23820E00, 0x58428D2A, 0x0C55F5EA, 0x1DADF43E, 0x233F7061, 0x3372F092,
			0x8D937E41, 0xD65FECF1, 0x6C223BDB, 0x7CDE3759, 0xCBEE7460, 0x4085F2A7, 0xCE77326E, 0xA6078084, 0x19F8509E,
			0xE8EFD855, 0x61D99735, 0xA969A7AA, 0xC50C06C2, 0x5A04ABFC, 0x800BCADC, 0x9E447A2E, 0xC3453484, 0xFDD56705,
			0x0E1E9EC9, 0xDB73DBD3, 0x105588CD, 0x675FDA79, 0xE3674340, 0xC5C43465, 0x713E38D8, 0x3D28F89E, 0xF16DFF20,
			0x153E21E7, 0x8FB03D4A, 0xE6E39F2B, 0xDB83ADF7 },

	KS2 = { 0xE93D5A68, 0x948140F7, 0xF64C261C, 0x94692934, 0x411520F7, 0x7602D4F7, 0xBCF46B2E, 0xD4A20068, 0xD4082471,
			0x3320F46A, 0x43B7D4B7, 0x500061AF, 0x1E39F62E, 0x97244546, 0x14214F74, 0xBF8B8840, 0x4D95FC1D, 0x96B591AF,
			0x70F4DDD3, 0x66A02F45, 0xBFBC09EC, 0x03BD9785, 0x7FAC6DD0, 0x31CB8504, 0x96EB27B3, 0x55FD3941, 0xDA2547E6,
			0xABCA0A9A, 0x28507825, 0x530429F4, 0x0A2C86DA, 0xE9B66DFB, 0x68DC1462, 0xD7486900, 0x680EC0A4, 0x27A18DEE,
			0x4F3FFEA2, 0xE887AD8C, 0xB58CE006, 0x7AF4D6B6, 0xAACE1E7C, 0xD3375FEC, 0xCE78A399, 0x406B2A42, 0x20FE9E35,
			0xD9F385B9, 0xEE39D7AB, 0x3B124E8B, 0x1DC9FAF7, 0x4B6D1856, 0x26A36631, 0xEAE397B2, 0x3A6EFA74, 0xDD5B4332,
			0x6841E7F7, 0xCA7820FB, 0xFB0AF54E, 0xD8FEB397, 0x454056AC, 0xBA489527, 0x55533A3A, 0x20838D87, 0xFE6BA9B7,
			0xD096954B, 0x55A867BC, 0xA1159A58, 0xCCA92963, 0x99E1DB33, 0xA62A4A56, 0x3F3125F9, 0x5EF47E1C, 0x9029317C,
			0xFDF8E802, 0x04272F70, 0x80BB155C, 0x05282CE3, 0x95C11548, 0xE4C66D22, 0x48C1133F, 0xC70F86DC, 0x07F9C9EE,
			0x41041F0F, 0x404779A4, 0x5D886E17, 0x325F51EB, 0xD59BC0D1, 0xF2BCC18F, 0x41113564, 0x257B7834, 0x602A9C60,
			0xDFF8E8A3, 0x1F636C1B, 0x0E12B4C2, 0x02E1329E, 0xAF664FD1, 0xCAD18115, 0x6B2395E0, 0x333E92E1, 0x3B240B62,
			0xEEBEB922, 0x85B2A20E, 0xE6BA0D99, 0xDE720C8C, 0x2DA2F728, 0xD0127845, 0x95B794FD, 0x647D0862, 0xE7CCF5F0,
			0x5449A36F, 0x877D48FA, 0xC39DFD27, 0xF33E8D1E, 0x0A476341, 0x992EFF74, 0x3A6F6EAB, 0xF4F8FD37, 0xA812DC60,
			0xA1EBDDF8, 0x991BE14C, 0xDB6E6B0D, 0xC67B5510, 0x6D672C37, 0x2765D43B, 0xDCD0E804, 0xF1290DC7, 0xCC00FFA3,
			0xB5390F92, 0x690FED0B, 0x667B9FFB, 0xCEDB7D9C, 0xA091CF0B, 0xD9155EA3, 0xBB132F88, 0x515BAD24, 0x7B9479BF,
			0x763BD6EB, 0x37392EB3, 0xCC115979, 0x8026E297, 0xF42E312D, 0x6842ADA7, 0xC66A2B3B, 0x12754CCC, 0x782EF11C,
			0x6A124237, 0xB79251E7, 0x06A1BBE6, 0x4BFB6350, 0x1A6B1018, 0x11CAEDFA, 0x3D25BDD8, 0xE2E1C3C9, 0x44421659,
			0x0A121386, 0xD90CEC6E, 0xD5ABEA2A, 0x64AF674E, 0xDA86A85F, 0xBEBFE988, 0x64E4C3FE, 0x9DBC8057, 0xF0F7C086,
			0x60787BF8, 0x6003604D, 0xD1FD8346, 0xF6381FB0, 0x7745AE04, 0xD736FCCC, 0x83426B33, 0xF01EAB71, 0xB0804187,
			0x3C005E5F, 0x77A057BE, 0xBDE8AE24, 0x55464299, 0xBF582E61, 0x4E58F48F, 0xF2DDFDA2, 0xF474EF38, 0x8789BDC2,
			0x5366F9C3, 0xC8B38E74, 0xB475F255, 0x46FCD9B9, 0x7AEB2661, 0x8B1DDF84, 0x846A0E79, 0x915F95E2, 0x466E598E,
			0x20B45770, 0x8CD55591, 0xC902DE4C, 0xB90BACE1, 0xBB8205D0, 0x11A86248, 0x7574A99E, 0xB77F19B6, 0xE0A9DC09,
			0x662D09A1, 0xC4324633, 0xE85A1F02, 0x09F0BE8C, 0x4A99A025, 0x1D6EFE10, 0x1AB93D1D, 0x0BA5A4DF, 0xA186F20F,
			0x2868F169, 0xDCB7DA83, 0x573906FE, 0xA1E2CE9B, 0x4FCD7F52, 0x50115E01, 0xA70683FA, 0xA002B5C4, 0x0DE6D027,
			0x9AF88C27, 0x773F8641, 0xC3604C06, 0x61A806B5, 0xF0177A28, 0xC0F586E0, 0x006058AA, 0x30DC7D62, 0x11E69ED7,
			0x2338EA63, 0x53C2DD94, 0xC2C21634, 0xBBCBEE56, 0x90BCB6DE, 0xEBFC7DA1, 0xCE591D76, 0x6F05E409, 0x4B7C0188,
			0x39720A3D, 0x7C927C24, 0x86E3725F, 0x724D9DB9, 0x1AC15BB4, 0xD39EB8FC, 0xED545578, 0x08FCA5B5, 0xD83D7CD3,
			0x4DAD0FC4, 0x1E50EF5E, 0xB161E6F8, 0xA28514D9, 0x6C51133C, 0x6FD5C7E7, 0x56E14EC4, 0x362ABFCE, 0xDDC6C837,
			0xD79A3234, 0x92638212, 0x670EFA8E, 0x406000E0 },

	KS3 = { 0x3A39CE37, 0xD3FAF5CF, 0xABC27737, 0x5AC52D1B, 0x5CB0679E, 0x4FA33742, 0xD3822740, 0x99BC9BBE, 0xD5118E9D,
			0xBF0F7315, 0xD62D1C7E, 0xC700C47B, 0xB78C1B6B, 0x21A19045, 0xB26EB1BE, 0x6A366EB4, 0x5748AB2F, 0xBC946E79,
			0xC6A376D2, 0x6549C2C8, 0x530FF8EE, 0x468DDE7D, 0xD5730A1D, 0x4CD04DC6, 0x2939BBDB, 0xA9BA4650, 0xAC9526E8,
			0xBE5EE304, 0xA1FAD5F0, 0x6A2D519A, 0x63EF8CE2, 0x9A86EE22, 0xC089C2B8, 0x43242EF6, 0xA51E03AA, 0x9CF2D0A4,
			0x83C061BA, 0x9BE96A4D, 0x8FE51550, 0xBA645BD6, 0x2826A2F9, 0xA73A3AE1, 0x4BA99586, 0xEF5562E9, 0xC72FEFD3,
			0xF752F7DA, 0x3F046F69, 0x77FA0A59, 0x80E4A915, 0x87B08601, 0x9B09E6AD, 0x3B3EE593, 0xE990FD5A, 0x9E34D797,
			0x2CF0B7D9, 0x022B8B51, 0x96D5AC3A, 0x017DA67D, 0xD1CF3ED6, 0x7C7D2D28, 0x1F9F25CF, 0xADF2B89B, 0x5AD6B472,
			0x5A88F54C, 0xE029AC71, 0xE019A5E6, 0x47B0ACFD, 0xED93FA9B, 0xE8D3C48D, 0x283B57CC, 0xF8D56629, 0x79132E28,
			0x785F0191, 0xED756055, 0xF7960E44, 0xE3D35E8C, 0x15056DD4, 0x88F46DBA, 0x03A16125, 0x0564F0BD, 0xC3EB9E15,
			0x3C9057A2, 0x97271AEC, 0xA93A072A, 0x1B3F6D9B, 0x1E6321F5, 0xF59C66FB, 0x26DCF319, 0x7533D928, 0xB155FDF5,
			0x03563482, 0x8ABA3CBB, 0x28517711, 0xC20AD9F8, 0xABCC5167, 0xCCAD925F, 0x4DE81751, 0x3830DC8E, 0x379D5862,
			0x9320F991, 0xEA7A90C2, 0xFB3E7BCE, 0x5121CE64, 0x774FBE32, 0xA8B6E37E, 0xC3293D46, 0x48DE5369, 0x6413E680,
			0xA2AE0810, 0xDD6DB224, 0x69852DFD, 0x09072166, 0xB39A460A, 0x6445C0DD, 0x586CDECF, 0x1C20C8AE, 0x5BBEF7DD,
			0x1B588D40, 0xCCD2017F, 0x6BB4E3BB, 0xDDA26A7E, 0x3A59FF45, 0x3E350A44, 0xBCB4CDD5, 0x72EACEA8, 0xFA6484BB,
			0x8D6612AE, 0xBF3C6F47, 0xD29BE463, 0x542F5D9E, 0xAEC2771B, 0xF64E6370, 0x740E0D8D, 0xE75B1357, 0xF8721671,
			0xAF537D5D, 0x4040CB08, 0x4EB4E2CC, 0x34D2466A, 0x0115AF84, 0xE1B00428, 0x95983A1D, 0x06B89FB4, 0xCE6EA048,
			0x6F3F3B82, 0x3520AB82, 0x011A1D4B, 0x277227F8, 0x611560B1, 0xE7933FDC, 0xBB3A792B, 0x344525BD, 0xA08839E1,
			0x51CE794B, 0x2F32C9B7, 0xA01FBAC9, 0xE01CC87E, 0xBCC7D1F6, 0xCF0111C3, 0xA1E8AAC7, 0x1A908749, 0xD44FBD9A,
			0xD0DADECB, 0xD50ADA38, 0x0339C32A, 0xC6913667, 0x8DF9317C, 0xE0B12B4F, 0xF79E59B7, 0x43F5BB3A, 0xF2D519FF,
			0x27D9459C, 0xBF97222C, 0x15E6FC2A, 0x0F91FC71, 0x9B941525, 0xFAE59361, 0xCEB69CEB, 0xC2A86459, 0x12BAA8D1,
			0xB6C1075E, 0xE3056A0C, 0x10D25065, 0xCB03A442, 0xE0EC6E0E, 0x1698DB3B, 0x4C98A0BE, 0x3278E964, 0x9F1F9532,
			0xE0D392DF, 0xD3A0342B, 0x8971F21E, 0x1B0A7441, 0x4BA3348C, 0xC5BE7120, 0xC37632D8, 0xDF359F8D, 0x9B992F2E,
			0xE60B6F47, 0x0FE3F11D, 0xE54CDA54, 0x1EDAD891, 0xCE6279CF, 0xCD3E7E6F, 0x1618B166, 0xFD2C1D05, 0x848FD2C5,
			0xF6FB2299, 0xF523F357, 0xA6327623, 0x93A83531, 0x56CCCD02, 0xACF08162, 0x5A75EBB5, 0x6E163697, 0x88D273CC,
			0xDE966292, 0x81B949D0, 0x4C50901B, 0x71C65614, 0xE6C6C7BD, 0x327A140A, 0x45E1D006, 0xC3F27B9A, 0xC9AA53FD,
			0x62A80F00, 0xBB25BFE2, 0x35BDD2F6, 0x71126905, 0xB2040222, 0xB6CBCF7C, 0xCD769C2B, 0x53113EC0, 0x1640E3D3,
			0x38ABBD60, 0x2547ADF0, 0xBA38209C, 0xF746CE76, 0x77AFA1C5, 0x20756060, 0x85CBFE4E, 0x8AE88DD8, 0x7AAAF9B0,
			0x4CF9AA7E, 0x1948C25C, 0x02FB8A8C, 0x01C36AE4, 0xD6EBE1F9, 0x90D4F869, 0xA65CDEA0, 0x3F09252D, 0xC208E69F,
			0xB74E6132, 0xCE77E25B, 0x578FDFE3, 0x3AC372E6 };

	// ====================================
	// Useful constants
	// ====================================

	private static final int ROUNDS = 16;
	private static final int BLOCK_SIZE = 8; // bytes = 64 bits
	private static final int SBOX_SK = 256;
	private static final int P_SZ = ROUNDS + 2;

	private final int[] S0, S1, S2, S3; // the s-boxes
	private final int[] P; // the p-array

	private boolean doEncrypt = false;

	private byte[] workingKey = null;

	public BlowFish()
	{
		S0 = new int[SBOX_SK];
		S1 = new int[SBOX_SK];
		S2 = new int[SBOX_SK];
		S3 = new int[SBOX_SK];
		P = new int[P_SZ];
	}

	/**
	 * initialise a Blowfish cipher.
	 * 
	 * @param encrypting
	 *            whether or not we are for encryption.
	 * @param key
	 *            the key required to set up the cipher.
	 * @exception IllegalArgumentException
	 *                if the params argument is inappropriate.
	 */
	public void init(boolean encrypting, byte[] key)
	{
		this.doEncrypt = encrypting;
		this.workingKey = key;
		setKey(this.workingKey);
	}

	public String getAlgorithmName()
	{
		return "Blowfish";
	}

	public final void transformBlock(byte[] in, int inOff, byte[] out, int outOff)
	{
		if (workingKey == null)
		{
			throw new IllegalStateException("Blowfish not initialised");
		}

		if (doEncrypt)
		{
			encryptBlock(in, inOff, out, outOff);
		}
		else
		{
			decryptBlock(in, inOff, out, outOff);
		}
	}

	public void reset()
	{
	}

	public int getBlockSize()
	{
		return BLOCK_SIZE;
	}

	// ==================================
	// Private Implementation
	// ==================================

	private int F(int x)
	{
		return (((S0[(x >>> 24)] + S1[(x >>> 16) & 0xff]) ^ S2[(x >>> 8) & 0xff]) + S3[x & 0xff]);
	}

	/**
	 * apply the encryption cycle to each value pair in the table.
	 */
	private void processTable(int xl, int xr, int[] table)
	{
		int size = table.length;

		for (int s = 0; s < size; s += 2)
		{
			xl ^= P[0];

			for (int i = 1; i < ROUNDS; i += 2)
			{
				xr ^= F(xl) ^ P[i];
				xl ^= F(xr) ^ P[i + 1];
			}

			xr ^= P[ROUNDS + 1];

			table[s] = xr;
			table[s + 1] = xl;

			xr = xl; // end of cycle swap
			xl = table[s];
		}
	}

	private void setKey(byte[] key)
	{
		/*
		 * - comments are from _Applied Crypto_, Schneier, p338 please be
		 * careful comparing the two, AC numbers the arrays from 1, the enclosed
		 * code from 0.
		 * 
		 * (1) Initialise the S-boxes and the P-array, with a fixed string This
		 * string contains the hexadecimal digits of pi (3.141...)
		 */
		System.arraycopy(KS0, 0, S0, 0, SBOX_SK);
		System.arraycopy(KS1, 0, S1, 0, SBOX_SK);
		System.arraycopy(KS2, 0, S2, 0, SBOX_SK);
		System.arraycopy(KS3, 0, S3, 0, SBOX_SK);

		System.arraycopy(KP, 0, P, 0, P_SZ);

		/*
		 * (2) Now, XOR P[0] with the first 32 bits of the key, XOR P[1] with
		 * the second 32-bits of the key, and so on for all bits of the key (up
		 * to P[17]). Repeatedly cycle through the key bits until the entire
		 * P-array has been XOR-ed with the key bits
		 */
		int keyLength = key.length;
		int keyIndex = 0;

		for (int i = 0; i < P_SZ; i++)
		{
			// get the 32 bits of the key, in 4 * 8 bit chunks
			int data = 0x0000000;
			for (int j = 0; j < 4; j++)
			{
				// create a 32 bit block
				data = (data << 8) | (key[keyIndex++] & 0xff);

				// wrap when we get to the end of the key
				if (keyIndex >= keyLength)
				{
					keyIndex = 0;
				}
			}
			// XOR the newly created 32 bit chunk onto the P-array
			P[i] ^= data;
		}

		/*
		 * (3) Encrypt the all-zero string with the Blowfish algorithm, using
		 * the subkeys described in (1) and (2)
		 * 
		 * (4) Replace P1 and P2 with the output of step (3)
		 * 
		 * (5) Encrypt the output of step(3) using the Blowfish algorithm, with
		 * the modified subkeys.
		 * 
		 * (6) Replace P3 and P4 with the output of step (5)
		 * 
		 * (7) Continue the process, replacing all elements of the P-array and
		 * then all four S-boxes in order, with the output of the continuously
		 * changing Blowfish algorithm
		 */

		processTable(0, 0, P);
		processTable(P[P_SZ - 2], P[P_SZ - 1], S0);
		processTable(S0[SBOX_SK - 2], S0[SBOX_SK - 1], S1);
		processTable(S1[SBOX_SK - 2], S1[SBOX_SK - 1], S2);
		processTable(S2[SBOX_SK - 2], S2[SBOX_SK - 1], S3);
	}

	/**
	 * Encrypt the given input starting at the given offset and place the result
	 * in the provided buffer starting at the given offset. The input will be an
	 * exact multiple of our blocksize.
	 */
	private void encryptBlock(byte[] src, int srcIndex, byte[] dst, int dstIndex)
	{
		int xl = BytesTo32bits(src, srcIndex);
		int xr = BytesTo32bits(src, srcIndex + 4);

		xl ^= P[0];

		for (int i = 1; i < ROUNDS; i += 2)
		{
			xr ^= F(xl) ^ P[i];
			xl ^= F(xr) ^ P[i + 1];
		}

		xr ^= P[ROUNDS + 1];

		Bits32ToBytes(xr, dst, dstIndex);
		Bits32ToBytes(xl, dst, dstIndex + 4);
	}

	/**
	 * Decrypt the given input starting at the given offset and place the result
	 * in the provided buffer starting at the given offset. The input will be an
	 * exact multiple of our blocksize.
	 */
	private void decryptBlock(byte[] src, int srcIndex, byte[] dst, int dstIndex)
	{
		int xl = BytesTo32bits(src, srcIndex);
		int xr = BytesTo32bits(src, srcIndex + 4);

		xl ^= P[ROUNDS + 1];

		for (int i = ROUNDS; i > 0; i -= 2)
		{
			xr ^= F(xl) ^ P[i];
			xl ^= F(xr) ^ P[i - 1];
		}

		xr ^= P[0];

		Bits32ToBytes(xr, dst, dstIndex);
		Bits32ToBytes(xl, dst, dstIndex + 4);
	}

	private int BytesTo32bits(byte[] b, int i)
	{
		return ((b[i] & 0xff) << 24) | ((b[i + 1] & 0xff) << 16) | ((b[i + 2] & 0xff) << 8) | ((b[i + 3] & 0xff));
	}

	private void Bits32ToBytes(int in, byte[] b, int offset)
	{
		b[offset + 3] = (byte) in;
		b[offset + 2] = (byte) (in >> 8);
		b[offset + 1] = (byte) (in >> 16);
		b[offset] = (byte) (in >> 24);
	}

}
